Protective slab for concrete bodies



Mgrch 5, 1935. J. w. B. BLACKMAN PROTECTIVE SLAB FOR CONCRETE BODIES 2sheets-Sheet 1 Filed April 21, 193s u Znvelzfor.

Jah/u H B. Blackman/ fr/76g March 5, 1935. J. w. B. BLACKMAN 1,993,294

PROTECTIVE SLA FOR CONCRETE BODIES Filed April 21, 1953 2 Sheets-Sheet 236 j? Dner/afar; Jo/lm W Eff/mim an/ Patented Mar. 5f, 1935 v i UNITEDSTATES PATENT OFFICE i2 PROTECTIVE SLAB FOR CONCRETE BODIES John W. B.Blackman, Long Beach, Calif. Application April 21, 19323, Serial No.667,251

16 Claims. (Cl. 726-18) This invention relates generally to protectedprovide for the formation o'fjoin'ts between slabs concretestructures inwhich concrete Walls, dams, arranged at special angles. floors, concretepiling and the like, are rendered The above mentioned and additionalobjects .of immune to the deleterious actionof such agencies theinvention, as well as the features and details 5 as sea water, acids andalkalies, and also the eiect of certain typical and preferredembodiments 5,

of frost in rupturing the concrete where'water is thereof, will beunderstood most readily without allowed to penetrate the pores, by theapplication need for further preliminary discussion, from the to suchstructures of preformed slag members following description. Throughoutthe descripimpregnated with waterproofing material and tion reference ismade to the accompanying l connected by waterproof joints. In its moredrawings, in whlchz, f l 10 specific aspects, the invention deals inimprove- Fig. lis a side view cfa typical, preferred form ments. uponthe types of slabs and joints comofzslab embodying the invention;prising the subject matter of my copending ap- Fig. 2 is a section online 2--2 of Fig. 1;' plication on Protected concrete structures, Ser.Fig. 3 is a fragmentary enlarged section on line l5 No. 587,702, filedJan. 20, 1932, now issued as 3a3 of Fig. 1; 154,

Patent No. 1,953,920, dated April ,10, 1934. Fig. 4 is a viewsimilar toFig. 3, showingV a 'I'heprincipal objects of the invention aredivariational form `of the invention; rected to improvements in slabs'of the character Fig. 5 is a sectional view showing a series of stated,whereby more secure bonds .with the body the slabs applied toa concretebody, and. illusof concrete to which they are applied, may be hadtrating the joint formation between adjacent 20 without lessening thestrength and reifectiveness slabs;

l of the joints between the slabs. The Ainvention Fig. 6 is a viewsimilarv to Fig. 5, taken onl line may be characterized as animprovementupon 6-6 of the latter; 1 slabs 'having undercut or dovetailed recessesfor Fig- 'l is a sectional view showing an arrange-j bonding to .thebody of the structure to which ment of slabs at special anglesfor liningsewers,;25

the slabs are applied. Heretoiore, it has been tunnels-and the like; andy customary to extend `key recesses continuously Fig 8 is a fragmentarysection on line 8--8xof through the slab, with the result that thethick- Fig. 7. l Y l l ness of theportions of the slab at the ends whereReferringfflrst to Figs. v1 and 2, my preferredv S0 the key way opens,are so reduced that it becomes form of slab, generally indicated at l0,vis shown@v 30 difiicult, and in some cases impossible, to .obtain to besubstantially rectangular in shape, and tto an effective joint betweensuch end portions of have plane surfaces 11 and 12, between which theslabs. This is due to fact that a satisfactory. the slab is ofsubstantially uniform thickness. It joint must be of greater depth thanthe remainwill be understood that the invention in its broad S5 ingthickness of the slabat its ends, `after the aspects is by nomeans-limited to slabs having 35-4 key way has been cut clear through.Although it the particular shape or dimensional characterwould bepossible even under such circumstances, istics of the illustrated forms,though for, most to increase the depth of the joint by making thepurposes, these shapes may belused to best adslab of greater thickness,this would be impractivantage.

40 cal in the majority of cases because of the result- Being designed toprotect concrete bodiesA 40 ant increase in bulkand weight of the slabsand against dBStTuOtiVe. aCGiOn OfaCdS, alkaliea sea v material requiredfor their formation. Water, andthe like, and toalord such protection Inaccordance with the invention, I have vbeen by reason 0f tS beingimpregnated with substance able to obtain both the advantages of akeyrecess resistant t0 Such agencies, `the slabs are made of in the slabsand a full joint thickness at its ends, material having Such porosity ast0 permit their 45 byconflning the key recess exclusively within theimpregnation to a substantial depth. Ordinarily, slabs. In this manner,the slabs may be. formed the slabs will be made of porous concrete,although of minimum thickness and joined together with other material,such as a specially prepared 'por-` equal etfectiveness on all sides. Iam also able ous clay, of suillcient porosity for impregnation to formthe slabs with plane surfaces so as to and of required strength, may beused if desired/50 present, when applied to the concrete body, a''Ihechar'acteristics of the concrete from which smooth regular surface.the slabs are molded, and the methods enmloyedv OtherV objects have todo with novel developin forming them comprise no part of the presentments in Shaping the slabs at theirV edges to invention, but'I maymention that thse features facilitate-the forming of normal joints, andto are fully set out in my copendingapplications on 55..,

Impregnated slabs and method forming same, Ser. No. 668,379, lled April28, 1933, and Forms for molding slab members, Ser. No. 667,252, iiled oneven date herewith. Likewise, the methods which may be employed for thepurpose of impregnating the slabs with waterproong material, constituteno part of this invention, and any suitable process of impregnation maybe used, such as those now in commercial use. As typical of processesthat have been found to be successful for thepurpose of impregnatingcon# crete or like bodies, I may cite the processes described in LettersPatents No. 1,555,208 and No. 1,555,209, both granted Sept. 29, 1925 toFrank S. Honberger. By the methodsdisclosed in these patents, it ispossible to so thoroughly impreg nate concrete and other porous bodieswith asimpregnated body will be rendered substantially immune to thedeleterious action of the agencies hereinabovementioned.. y

The slab 10 is shown to be formed'with' a tongue 13 projecting from oneside and end thereof, andcomplementary rgrooves 14 formed in the otherside and end. Broadly speaking, the edges of the slab. may, ofzcourse,be shaped to provide any othersuitable joint connections betweenadjacent members.. 'A key recess, generally indicated at 16, is formedin one of the slab faces, the sides and ends'of the recess terminatingwithin the slab, as indicated. While the key recess may be of anysuitable shape, it preferably is substantially rectangular. Oppositesides of this recess are undercutas shown in Fig. 2 at 17, the purposeof the undercut being to afford a secure joint between the slab andabody of-concrete poured against it and into the recess, asI

shown in Fig. 5. i

- In Figs. 3 and 6, the ends 18 of the key recess Iare shown to slopeinwardly Atoward the base 19 of the recess, the reason for so slopingthe shoul-` ders at 18, being to allow' complete drainage of asphaltfromv the recess at the 'conclusion of the impregnating process.' Inaccordancewith'my present practice, I stand the slabs on end in a bathof the waterproofing substance, in the op'eration of impregnating. Afterimpregnation has become complete, the slabs are removed from the bath,whereupon any of the hot waterproong material in recess 16,' will draintherefrom completely, as permitted by the outward slope Vof undercut, aswell asthe sides 17, as I have indi` cated in Fig. 4 wherein the ends18a. are shown tol `be dove-tailedin a manner similar` to the sides.

It will be. noted that beyond the ends of the keyrecess 16, the slab hasthe same full thickness as it has at the sides of the recess, and thatthe ,i joint thickness at the ends vof the slab corresponds to thethickness at its sides. As I have previously mentioned, while undercutkey ways have been heretofore formed in slab members of this generalcharacter, it has been the practice to extend thev key way entirelythrough the slab so that the way opens at the ends` of the slab. A s aresult, it has been impossible to secure the same effective jointsbetween the ends of theslabsas at their sides, since the jointthicknessat the ends of the key` '.ways has been reduced to a distancecorresponde` ing to the thickness between the base surface 19 of therecess and the slab face 12. As will be apparent, in accordance with theinvention, the joints between adjacent ends of the slabs are equal ineffectiveness to the joints between side edges.

In Figs. 5 and 6, I have shown the slabs applied to a concrete body insuch manner as to protect the latter from deterioration. Inconstruction, the slabs are arranged edgeto edge in the mannerillustrated, and joined together by waterproofing material 20 placed inthe joint spaces between adjacent slab members. As I have stated, theslabs before being applied to the concrete body, are impregnated withwaterproofing substance, typically and preferably asphalt. The jointfilling material 20 is of a character such that it will not only form abond between the material or concrete from which the slabs are formed,but also such that it will become substantially integrated with thematerial with which the slabs. are impregnated. f Asphalt isthepreferred joint iillingv material. Ordinarily, a low penetrationasphalt willbe used, and the asphalt, after first being heated to atemperature above the melting point of the asphalt with which the slabsare impregnated, is poured into the joint space. asphalt poured into.the joint melts theimpregnating asphalt at the joint surfaces, causingboth,

asphalts to ow together to the extent that the joint filling asphalt,when cooled and hardened, will have become integrated or .madecontinuous with the impregnating asphalt, in addition to having bondedor adhered to the concrete of the slabs.

After the slabs havebeen thus joined, the concrete is poured againstthem, `llirig the key recesses 16 as indicated. Having rst beenassembled or erected .prior to pouring the concrete, the slabs serve, inone aspect, asa permanent form for the concrete. By virtue of theimperviousness of the slabs and joints, and the immunity of theimpregnating and joint lling substance to attack by the common agenciesresponsible for deterioration of concrete, the body of concrete 21 isfully protected from the destructive effect of fluids to which the slabsmay be exposed.

In view of the desirability that the joint between the ends of the slabcorrespond in thickness to the joint between the side edges, it will beseen that the joint structure has a deiinite relation to the form of keyrecess WhichI have illustrated. The desired efficiency of thejoint astostrength and waterproofness, is largely dee. pendent upon the fulljoint thickness which has been attained by discontinuing the key recessas into the top edge groove, ofi the lower slab and then placing theupper slab in position, the waterproofing material running freelythroughout the full length'of the joint.: -For horizontal joints,

the`tongues.13 and groove 14 preferably have' the relative shapesindicated. i l

inasmuch as both slabs must be placed in position before the verticaljoints can be poured, and

since these joints may be of such length that' Where the jointspace isrestricted, the waterproofing material after being poured into the topof the joint may vcool before reaching' the bottom'thereof, it sometimesbecomes desirable to increase the'cross sectional area of the vertical.

action of iiiuids which the tunnel may carryiun' joint spaces.Accordingly, as indicated. in Fig. 6, I provide for increased space iat.26 in thervertical joints, by beveling the face 13a of thetongue 13,the clearance at 27, however, preferably re'- rnaining substantially thesame as inthe corre-1 sponding part of the Vhorizontally.runningjoints.l

Sharp `corners andv edges .onthe 'tongue and groove parts of the slabwhich might Yresult shapes to enable their arrangementvat special anglesas required'for 4tunnel lining.'r In forming the tunnel, the concrete 30at the bottom is iirst poured, and the floor slabs 31 placedon thewetconcrete. Slabs 31 may be provided with semicircular grooves 32 for thepurpose of bonding to the concrete 30, and adjacent ends 'of the slabsmay be beveled asvindicated, to form a downwardly tapering opening at 33into which waterproofing material may be poured. At the time slabs 3lare laid, lower side slabs 34 may also be laid on the fresh concretek3Q, these slabs alsov having the bonding grooves 32, but having specialshapes at their upper and lower Aedges to form special joints withthefloor slabs 31 and the ver.

tically positioned side slabs 35. The latter is shaped in accordancewith the lpreviously described slab illustrated in Fig. l. The loweredge 34a of slab 34 is beveled as indicated, to form, with the adjacentedge of slab 3l, a downwardly tapering space to receive the jointiilling material; "I'he upper edge of slab 34 is beveledat an angle withthe faces of the slab, and has formed therein a groove 34h to receivetongue 13 on the lower edge of slab 35, and the outer face of slab 34 isbeveled at 34e to aline with the outer face of slab 35.

The upper inclined slab 36 is shaped generally similar to slab 34, beingprovided, however, with.

a key type recess 37, instead of semi-circular grooves, and having atitslower edge a tongue 36a projecting into the groove inthe upper edge ofslab 35. The roof'iof the tunnel is lined with slabs 39 havingdovetailed key recesses 40, and beveled ends forming kdownwardlytapering joint spaces at 4l. VSimilarly shaped joint spaces arer formedat 42between the edges'of slabs 36 and 39.1

As previously mentioned, slabs 31 and 34 are rst laid upon the freshconcrete 30 in the bottom of the tunnel. Thereafter slabs 35, 36 and 39are arranged in the positionsy illustrated by supwhereas thecorresponding joints between slabs 31, 34, 36 and 39 will besubstantially as indicated in Fig. 8, the lateral edges of the slabsbeing beveled to form spaces 46 into which the joint material may bepoured from above.

After the joint material has hardened, concrete is then poured againstthe outer faces of slabs 35, 36 and 39, as illustrated, the concretefilling the key recesses so that after the concrete has set and theforms are removed, the slabs will be securely held in place. By reasonof the slabs being thoroughly impregnated and the joints filled withwaterproong material, the tunnel or conduit is given a lining affordingthe concrete complete protection against the deleterious der conditionsof use.v

I claim 1. A slab member of the character described, having formed in`one of its faces a key recess,.` the sides and endsof which terminatewithinsaid slab, opposite sides of lsaid recess being undercut to form akey for bondingto` material poured intothe recess and one end of saidrecessbeing bev-.f eled inwardly toward the base 'thereof at an angleAopposite the angularity of the undercut at. the.

sides of the recess.

2. A slab :member of the character described, having formed in one ofits faces a key recess;l the sides and ends of whichterminate'withinsaid slab, opposite sides of said recess being undercut: to form a keyfor bonding to material poured into the recess, and the ends of saidrecess being beveled inwardly towardV the base thereofv zat Sani` angleopposite the angularity of the undercut aty the sides of the recess. f

3. A slab member of the character described, havingformed in one of itsfaces a key recess,

the sides and ends of which terminate within said slab, opposite sidesof Ysaid recess being undercut to form a key for bonding to materialpoured into the recess, tongues'projecting fromone side and end of theslab, and grooves formedin the other side and end thereof, the thicknessof the sides and ends ofthe slab adjacent said tonguesand grooves beingsubstantially uniform. y Y

4. A slab member vof the character described,

having formed in one oi its faces a key recess,-

stantially the iull maximum thickness of the slab.V

5. A slab member of the character described,

formed of concrete impregnated with asphalt and: havingiormed in one ofits faces a keyrecess,"

the'sides and ends of which terminate within said slab, opposite sidesof said recess being'undercutl to form a key for bonding to materialpouredi into the recess, and joint forming means on' the side and endedges of the slab, the sides and ends of the slab adjacent said jointforming means being of substantially uniform thickness.

.6. A slab member of the character described y having substantiallyplane surfaces and being of substantially uniform thickness between saidsurfaces,'there being formed in one of said surfacesy arectangular` keyrecess, the sides and ends'of which" terminate within the slab, oppositesides of.said recess being undercut toform 'a key 'for' bondingtomaterial poured into the recess and one end of saidrecess beingbeveledinwardly to' Ward the base thereof, tongues projecting `frompoured into the recess but at least one end of the recess having noundercut, said slab member being of uniform thickness beyond the sidesand ends of said recess, and joint forming means on the sides and endsof said member.

8. In structures of the character described, a

to concrete poured into the recess, the sides and.

ends of one of said members having tongue and Y groove joints with thesides'and ends of the other members, there being spaces between thesides and ends of said members to accommodate joint filling material,and said spaces being filled with Waterproofing substance integratedwith the substance with which said members are impregcomparatively widespace between the tongue and nated, the joint thicknesses aty both thesides and ends of adjacent slab members being sub,-

stantially the maximum thickness of the slab.

9. In structures of the character described, a

j ,l plurality of slab members formed of porous ma- 20 terialimpregnated with waterproofing substance, each of said members havingformed in one of its faces a key recess, the sides and ends of whichterminate within the members, each recess having an undercut side toform a key for bonding to concrete poured into the recess, the sides andends of one of said members having tongue and groove joints withhorizontally and vertically extending sides and ends of the othermembers,

p there being spaces between said members to accommodate joint fillingmaterial, and said spaces being lled with waterproofing substanceintegrated with the substance with which said members are impregnated,the spaces in the vertically extending joints being of larger crosssectional area than thespaces in the horizontally extending joints.

10. In structures of the character described, a pair of porous membersimpregnated with waterproofing material and joined together alongvertically extending edges, the joint between said members comprising agroove formed in one of said members, and a tongue on the other memberprojecting into said groove, there being a the base of said groove andcomparatively narrow spaces between the sides of the tongue and thesides of the groove, and waterproofing material filling the joint spaceand integrated with the material with which said members are im:-

pregnated.

11. In structures of the character described, a pair of porous membersimpregnated with Waterproofing material and joined together alongvertically extending edges, the joint between said members comprising agroove formed in one of said members, and a tongue on the other memberprojecting into said groove, the vertically extending tongues on saidslabs having beveled ends, and waterproofing material filling the jointspace and integrated with the material with which said members areimpregnated.

12. A slab member of the character described, having formed in one ofits faces a key recess, the sides and ends of which terminate withinsaid slab, opposite sides of said recess being undercut to form a keyfor bonding to material poured into the recess, one peripheral edge ofsaid slab being beveled at an angle with the faces thereof.

13. A slab member of the character described, having formed in one ,ofits faces a key recess, the sides and ends of which terminate Withinsaid slab, opposite sides of said recess being undercut to form a keyfor bonding to material poured into the recess, and a tongue projectingfrom one peripheral edge of said slab at an angle with the facesthereof.

14. A slab member of the character described, having formed in one ofits faces a key recess, the sides and ends of which terminate withinsaid slab, opposite sides of Ysaid recess being undercut to form a keyfor bonding to material poured into the recess,y one peripheral edge ofsaid slab being beveled at an angle with the faces thereof and theopposite peripheral edge of the slab having a tongue projecting at anangle with the faces of the slab.

l5. The combination comprising, a pair of slab4 members of the characterdescribed arranged edge to edge, veach slab having formed in one of itsfaces a key recess, the sides and ends of which terminate within theslab, opposite sides of the recess being undercut to form a key forbonding to material poured into the recess, joint edges extending alongopposite sides and ends of each slab, the thickness of both the sidesand ends of each slab adjacent said edges being substantially the fullmaximum thickness of the slab, the adjacent edges of said slabs beingshaped to form a downwardly tapering joint space, and joint formingmaterial filling said space.

16. The combination comprising, a pair of slab lmembers formed ofconcrete impregnated with Waterproofing material arranged edge Vto edge,each slab having formed in one of its faces a key recess, the sides andends of vwhich terminate within the slab, opposite sides of the recessbeing undercut to form a key for bonding to material poured into therecess, joint edges extending along opposite sides and ends of eachslab, thev

